Adjustable lamp-socket.



R. H. WELLES.

ADJUSTABLE LAMP SOCKET.

APPLICATION FILED NOV- 19, 1915.

1,201,405. Patented Oct. 17,1916.

UNITED STATES Pa rENT OFFICE.

RICHARD H. WELLES, OF KENOSHA, WISCONSIN ASSIGNOR TO THE BADGER BRASSMFG. 00., OF KENOSHA, WISCONSIN, A CORPORATION OF WISCONSIN.

ADJUSTABLE LAMP-SOCKET.

Specification of Letters Patent.

Patented Oct. 17, 1916.

To all whom it may concern:

Be it known that I, RICHARD H. VVELLES, a citizen of the United States,residing at Kenosha, in the county of Kenosha and State of lVisconsin,have invented certain new and useful Improvements in AdjustableLamp-Sockets, of which'the following is a specification.

This invention relates to adjustable lamp sockets, and refersparticularly to lamp sockets adjustable axially for focusing thefilament of a lamp bulb, as in the parabolic reflector of an ordinaryautomobile electric search lamp.

The invention in its preferred form. is chiefly applicable to a type ofadjustable socket in which the lamp bulb is moved axially by means of anadjusting screw having its axis substantially parallel with the axis ofthe bulb; that is to say, the direction of movement of the lamp.

Among the salient objects of the invention are, to provide an adjustablelamp socket of the class described so organized that it may be adjustedin any axial position within the limits of the mechanism, and when soadjusted will retain its adjusted position without danger of movement,due to accidental shock or vibration; to provide a construction soorganized that it will allow an extremely fine and accurate adjustmentof the filament in its proper focal position; to provide a constructionof the class described Which shall be extremely simple in design,economical of manufacture, eflicient in operation, .and convenient tomanipulate; and, in general, to provide an improved construction of thecharacter referred to.

In the drawings Figure 1 is a fragmentary axial section taken through anautomobile search light to which my invention is applied; Fig. 2 is afragmentary section taken on the line 2--2 of Fig. 1; and Fig. 3 is afragmentary section taken on line 33 of Fig. 1.

In the drawings 10 represents the outer casing of the search lamp inwhich is nested the parabolic reflector 11. Coaxial with the focal axisof the parabolic reflector 11 is adjustably located the electric lampbulb 12 having a filament 13 movable in the axis of the reflector. Thelamp bulb 12 is furnished with the usual Ediswa'n or bayonet base 14fitted in a tubular socket 15, said socket 15 being axially slidableWithin a supporting tube 16 secured rigidly at 17 to the rear of 15 isflanged over slightly, as shown at 20,

to form a stop for the fiber washer 21 which is perforated in order toslidably receive the plunger screw 22. Said screw at its outer end isthreaded into the plunger contact 23 which engages and -makes anelectrical connection with the contact button 19 on the base of thelamp. The plunger contact 23 is transversely perforated, as shown at 24,in order to admit the bare end of the line wire 25 which is clamped 1nposition by the outer end of the plunger screw 22 when the latter isscrewed home into the plunger 23. The contact plunger 23 is resilientlyforced outwardly against the contact button 19, thereby making anefficient electrical contact and at the same time holding the lamp basein position, by means of a coil compression spring 26, one end of whichabuts against the insulated washer 21, the other end of the springengaging one of the washers 27 and 28 which maintain the outer end ofthe plunger in its central position.

In the under side of the supporting tube 16 is an open-ended slot 29 inwhich slides the downwardly projecting limb 30 of the angle piece 31which is secured to the under side of the socket 15 as by a screw orrivet 32. The limb 30 is drilled and tapped to accommodate the focusingscrew 33 which is preferably vertically beneath the socket and has itsaxis parallel with the axis of the supporting tube 16. The head 34: ofthe focusing screw is seated in a small recess pressed into the outsideof the casing 10, which is perforated to form a bearing for the neck ofsaid screw. The neck of the focusing screw also forms a support for thelocking spring35, which is apertured to freely admit said screw, and thescrew is prevented from moving outwardly of the casing by means of thehexagonal collar 36, which is soldered or otherwise secured to the neckof the screw, in such position that the spring 35 is maintained inposition and axial movement of the screw is substantially prevented. Thelower end of the spring 35 is formed into a loop and turned upwardly insuch position that the end-37 of the loop presses strongly against oneof the facets of the hexagonal collar 36, thereby preventing the latterfrom turning, except when a substantial amount of torsion is applied tothe screw. In order to prevent the spring 35 from spinning or turningupon the focusing screw 33 when the latter is rotated, I shape the upperend of said spring into a concave form, as shown at 38, so as to ratherclosely engage and partially embrace the outer periphery of thesupporting tube 16.

The device is extremely simple in its operation. When it is desired tochange the axial position of the filament 13, the screw 33, by means ofthe head 34, is rotated from the exterior of the casing in the properdirection to move the filament 13 as desired. The screw 33 operating inthe nut 30 causes the socket 15 to slide axially in the supportingtube16 as the screw is turned, axial movement of'the screw being preventedeither by the screw head 34 or the collar 36, depending upon thedirection in which the screw is turned. Except when the focusing screwis being rotated to adjust the bulb (this requiring' a considerableamount of torsional force), the end 37 of the spring engages one of thefacets on the hexagonal collar 36 and absolutely locks the screw againstrotary movement and renders the device secure against shocks orvibration. In addition, the upward pressure of the end 37 of the springagainst the collar 36 eliminates the possibility of any of the variousparts rattling around, due to any slight looseness in the mechanicalfit. It is self-evident that an extremely close and fine adjustment ofthe filament is possible by means of this device, since a complete turnof the screw includes six possible different positions of the filament,one for each face of the hexagonal collar 36. In practice, I make thespring 35 of substantial strength so that it is not possible to turn thescrew 33 without the aid of a screw driver, thereby largely eliminatingthe danger of mischievous persons tampering with the bulb adjustment.

Inasmuch as the described details of construction are capable ofmodification without sacrifice of efliciency, the scope of the inventionmust be determined by reference to the appended claims.

clalm:

1. In a focusing device, a supporting casing, a sliding socketadjustable in said supporting casing, a lamp for said sliding socket, aplunger s crew within said socket; insulating washers at each end ofsaid socket .for supporting said screw, a plunger contact locatedbetween the plunger and the base of the lamp and into which said plunger screw projects and having a transverse opening for the admittance ofthe line wire, said line wire held inposition in said opening by saidplunger screw, and a spring for maintaining connection between'saidplunger contact and said lamp.

2. In a focusing device, an outer casing, an inwardly projecting slottedtubesecured in said casing, a socket slidable in said tube provided withan aperture, a spring pressed plunger slidable in said socket, a lamp inthe socket having a contact for engagement with the plunger, said wireconnected to the plunger and projecting through the socket aperture, anut secured to the socket and projecting through the slot in the tube,and a screw engaging said nut positioned againstendwise movementfor'sliding said socket, said screw having its axis parallel with theaxis of the tube.

3. In a focusing device, the combination of a supporting casing, a lampsocket slidable in said casing, a nut rigidly secured to and projectingradially outwardly from said socket, an adjusting screw having its axissubstantially parallel to the axis of said socket, engaging said nut,rotatable in but axially fixed in said casing, said screw being operablefrom the exterior of said casing, a member keyed to the exterior of saidscrew within said casing and having a circumferential engaging face, aflat plate spring perforated to rotatably admit said screw, and havingmeans engaging the casing to prevent rotation of sai spring, said springbeing provided with a part cooperating with and resiliently engagingsaid circumferential engaging portion on said keyed member withsufiicient force to prevent accidental rotation of said screw.

4. In a focusing device, the combination of an outer casing providedwith an inwardly extending, longitudinally slotted supporting tube, atubular lamp socket slidable in said tube, said socket havin securedthereto a nut projecting radlally through said slot, an adjusting screwhaving its axis substantially parallel to the axis of said tube andengaging said nut, said screw being rotatably supported in saidcasingand having an outer head, a collar on said screw within saidcasing and cooperating with said head and preventing outward movement ofsaid screw, and a nonrotatable flat plate spring resiliently engagingsaid collar, said collar and spring being suitably arranged to lock saidscrew against accidental movement.

5. In a focusing device, the combination of an outer casing providedwith an inwardly extending, longitudinally slotted supporting tube, atubular lamp socket slidable in said tube, said socket having securedthereto a nut projecting radially through said slot, an adjusting screwhaving its axis substantially parallel to the axis of said tube andengaging said nut, said screw being rotatably supported in said casingand having an outer head, a collar on said screw within said casing andcooperating with said head and preventing outward movement of saidscrew, and a flat plate spring perforated to rotatably admit said screwlocated between said collar and said casing, having means engaging saidcasing to prevent rotary movement of said spring on said screw, and.having a part resiliently engaging said collar, said collar beingprovided with a locking face cooperating with said spring to preventaccidental rotary movement of said screw.

6. In a focusing device, the combination of an outer casing providedwith an inwardly extending, longitudinally slotted supporting tube, atubular lamp socket slidable in said tube, said socket having securedthereto a nut projecting through said slot, an adjusting screw havingits axis substantially parallel to the axis of said tube and engagingsaid nut, said screw being ro tatably supported in said casing andhaving an outer head, a collar on said screw intermediate the casing andthe nut cooperating with said head and preventing outward movement ofsaid screw, and a flat plate spring perforated to rotatably admit saidscrew located between said collar and said casing, shaped to engage saidsupporting tube to prevent rotary movement of said spring on said screw,and having a part resiliently engaging said collar, said collar beingprovided with a locking face coperating w1th said spring to preventaccidental rotary movement of said screw.

RICHARD H. WELLES. Witnesses:

EMILIE Ross, C. A. SCANS.

